Brutal Doom 64

Brutal Doom 64 is a gore-themed modification for GZDoom and Zandronum, currently developed by Marcos Abenante (Sergeant Mark IV). The mod features new graphical effects such as smooth weapon animations, glowing particles and realistic lighting, recoil and "earthquake" effects onscreen, 3D blood animations, and more. Unlike Brutal Doom, this modification does not contain fatalities, focusing more on Doom 64's horror atmosphere. Brutal Doom 64 is compatible with The Ultimate Doom, Doom 2 and Final Doom.

Features

 * Revised weapon sprites
 * New weapons (such as a laser gun and assault rifle)
 * Enhanced enemy AI
 * Revised Doom 64 maps
 * Two player classes: "Classic" (for the original gameplay experience) and "Tactical" (includes an assault rifle, reloading mechanism, and possibly sprinting)
 * The classic enemies (such as the revenant). Arch-viles are not included.
 * The Hell hound is added; it was an unused enemy concept for the original Doom 64.
 * 64-player multiplayer support: co-op, survival co-op and deathmatch
 * Most content that was cut from Doom 64
 * New sky backgrounds

Weapon changes

 * Fists: No executions when using a Berserk Pack.
 * Chainsaw: Now has ammo and increased damage as of version 2.0.
 * Pistol: Increased firing rate and damage.
 * Shotgun: Pump action based on Doom's shotgun. Now shoots 10 pellets per shot instead of 7 therefore increasing damage.
 * Super shotgun: Break action, based on Doom's super shotgun. Increased damage. Alt-fire fires one barrel
 * Assault Rifle: An automatic weapon with a high fire rate and DPS, spread dramatically increases over prolonged periods of fire.
 * Chaingun: Longer barrel and a faster firing rate allowing for high DPS out to longer ranges.
 * Rocket launcher: Rockets are affected by gravity over long distances.
 * Plasma gun: Unknown.
 * BFG9000: Now deals splash damage, it is possible to kill yourself using it. As of version 2.0, its mechanics were reverted to fire off hitscan tracers after the projectile explodes.
 * Unmaker: Now has its own ammo system. Converted to a semi-automatic railgun-esque weapon with each shot dealing dramatically high damage depending on how upgraded it is.
 * Lasergun: Concentrated beam weapon that delivers consistent damage.

Enemy AI changes

 * Zombieman: New sprites showing a pistol.
 * Shotgun guy: Unknown.
 * Heavy weapon dude: Appears as a rogue red marine wielding a chaingun.
 * Imp: Increased walking speed and fireball speed. Possibly increased fireball damage and faster melee attack.
 * Nightmare imp: Extremely fast. Invisible until it stops moving or is idle. Possibly faster attack sequence.
 * Pinky: Faster walking speed and attack sequence.
 * Spectre: Faster movement. Invisible until it stops moving or is idle. Possibly faster attack sequence.
 * Cacodemon: Unknown.
 * Hell knight: Unknown.
 * Baron of Hell: Unknown
 * Pain elemental: Unknown.
 * Lost soul: Flame glows an orange aura.
 * Mancubus: Unknown.
 * Revenant: Slow and fires two rockets. Made from the early Revenant model shown here: http://romero.smugmug.com/Video-Games/The-Archives/i-8djkVsC/1/L/model_revenant-L.jpg
 * Arachnotron: Faster.
 * Spider mastermind: New sprite that looks like a larger Arachnotron with a skull based face. Armed with two Super Chainguns as opposed to one.
 * Cyberdemon: Fires rockets more frequently.
 * Mother demon: Unknown.
 * Hellhound: A two-headed giant skinless dog that is fast and spits two fireballs, one from each head.